When a user works with a computer (or a mobile device), he periodically backs up his personal data, such as collections of user pictures. However, before a backup of a large picture collection, some pictures (files) may get corrupted without the user knowing about it. This may occur due to viruses, because of hardware damages, because of data transmission errors, etc. When a backup starts, the data is already corrupted, and the corrupted data can unintentionally replace normal data on the storage/cloud, etc. In case of several hundreds or even thousands of pictures, a user will not be able to go over every single backed up picture to make sure it is not corrupted. The user files may get corrupted as a result of errors within the backup application, because of disk errors or due to malware.
Regardless of the cause, the pictures or files may become completely or partially un-viewable or un-readable. The undetected corrupted pictures will be stored in the disk backup until expiration of the backup retention period (e.g., approximately a year). After the expiration of the backup retention period all file archives (i.e., pictures) are deleted from the disk and the corrupted picture copies are left in the backup without a possibility of restoration of the original pictures. Then, the corrupted pictures can be backed up over and over and the user will never be able to find the originals. The conventional backup solutions do not check for validity of data being backed up during an incremental backup or a scheduled full backup.
Accordingly, an efficient method for backup and recovery of user data, which determines validity of data being backed up during an incremental backup or a scheduled full backup user, is desired.